let a = new Promise((resolve) => {
    console.log("a1");
    resolve("Promise a1.then")
})

let a1 = a.then((value) => {
    console.log(value);
    return "ok";
})
console.log(a);

console.log(a1);

a1.then((value)=>{
    console.log(value);
})

let b = new Promise((resolve) => {
    console.log("b1");
    resolve("Promise b1.then")
})

b.then((value) => {
    console.log(value);
    return "ok";
})